Question

The number of moles of ammonia that have the same mass as that of 3 moles of carbon dioxide is

Answer 1

Let me help you with this query.
It is given that there are 3 moles of carbon dioxide.
We have to calculate the number of moles of ammonia that have the same mass as that of 3 moles of carbon dioxide.
Solution:
Since, we know that,
Number of moles = Given mass / Molar mass  ....... (1)
1 mole of CO₂ = 12 + 16(2)
1 mole of CO₂ = 12 + 32
1 mole of CO₂ = 44 g
3 moles of CO₂ = 44 x 3 = 132 g
Molar mass of NH₃ = 14 + 1(3)
Molar mass of NH₃ = 14 + 3
Molar mass of NH₃ = 17 g
Now put these values in equation (1), we get:
Number of moles = Given mass / Molar mass
Number of moles = 132 / 17
Number of moles = 7.7 moles
which is the required answer.
Hence, 7.7 moles of ammonia have the same mass as that of 3 moles of carbon dioxide.
Hope it will help you.

Answer 2

Explanation :
Atomic mass of carbon=12u
oxygen=16u
molecular mass of CO2=12+2x16=12+32=44u
molar mass = 44g 

1mole of CO2 contains 44g

3 moles of CO2 ---?

=3x44/1=132g

Molar mass of NH3=14+3x1=17g

Formula : Number of moles= Given weight/molar mass
=132/17
=7.76 moles

 ∴Number of moles of ammonia that have the same mass as that of 3 moles of carbon dioxide is7.76 mol